Let’s face it: manufactureres of cleaning products are looking to sell their product, so the directions they give you for use may be overly generous in terms of what will work best and cheapest. Play around with the amount of product you use, gradually working down from the recommended amount to the point where the product ceases to work, then nudge the amount up a little bit. This will save you the most amount of money while still ensuring a product that “works as advertised.”